From b5837416b65ffef64986606dfa764f94ac485c15 Mon Sep 17 00:00:00 2001
From: serramatutu <lucas.paes@dbtlabs.com>
Date: Tue, 12 Nov 2024 15:41:06 +0100
Subject: [PATCH] feat: allow groupby-only queries

This commit adds support for group_by only adhoc queries with no
metrics. This has a similar effect to listing dimension values, and is
being added to the SDK for parity with what the ADBC and GraphQL APIs
can do already.

I changed the validation logic to allow for it, and I added test cases
for it.
---
 dbtsl/api/graphql/protocol.py    |  2 +-
 dbtsl/api/shared/query_params.py |  7 ++-----
 tests/query_test_cases.py        |  4 ++++
 tests/test_models.py             | 25 ++++++++++++++-----------
 4 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/dbtsl/api/graphql/protocol.py b/dbtsl/api/graphql/protocol.py
index d7faa3a..4115f99 100644
--- a/dbtsl/api/graphql/protocol.py
+++ b/dbtsl/api/graphql/protocol.py
@@ -219,7 +219,7 @@ def get_query_request_variables(environment_id: int, params: QueryParameters) ->
     if isinstance(strict_params, AdhocQueryParametersStrict):
         return {
             "savedQuery": None,
-            "metrics": [{"name": m} for m in strict_params.metrics],
+            "metrics": [{"name": m} for m in strict_params.metrics] if strict_params.metrics is not None else None,
             "groupBy": [{"name": g} for g in strict_params.group_by] if strict_params.group_by is not None else None,
             **shared_vars,
         }
diff --git a/dbtsl/api/shared/query_params.py b/dbtsl/api/shared/query_params.py
index 538de28..3537715 100644
--- a/dbtsl/api/shared/query_params.py
+++ b/dbtsl/api/shared/query_params.py
@@ -44,7 +44,7 @@ class QueryParameters(TypedDict, total=False):
 class AdhocQueryParametersStrict:
     """The parameters of an adhoc query, strictly validated."""
 
-    metrics: List[str]
+    metrics: Optional[List[str]]
     group_by: Optional[List[str]]
     limit: Optional[int]
     order_by: Optional[List[OrderBySpec]]
@@ -125,11 +125,8 @@ def validate_query_parameters(
             **shared_params,
         )
 
-    if "metrics" not in params or len(params["metrics"]) == 0:
-        raise ValueError("You need to specify at least one metric.")
-
     return AdhocQueryParametersStrict(
-        metrics=params["metrics"],
+        metrics=params.get("metrics"),
         group_by=params.get("group_by"),
         **shared_params,
     )
diff --git a/tests/query_test_cases.py b/tests/query_test_cases.py
index 70c4af8..7480937 100644
--- a/tests/query_test_cases.py
+++ b/tests/query_test_cases.py
@@ -17,6 +17,10 @@
     {
         "metrics": ["order_total"],
     },
+    # ad hoc query, only group by
+    {
+        "group_by": ["customer__customer_type"],
+    },
     # ad hoc query, metric and group by
     {
         "metrics": ["order_total"],
diff --git a/tests/test_models.py b/tests/test_models.py
index 49c3fff..3b98320 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -178,7 +178,7 @@ def test_validate_order_by_not_found() -> None:
         validate_order_by(["a"], ["b"], "c")
 
 
-def test_validate_query_params_adhoc_query_valid() -> None:
+def test_validate_query_params_adhoc_query_valid_metrics_and_groupby() -> None:
     p: QueryParameters = {
         "metrics": ["a", "b"],
         "group_by": ["c", "d"],
@@ -197,6 +197,18 @@ def test_validate_query_params_adhoc_query_valid() -> None:
     assert not r.read_cache
 
 
+def test_validate_query_params_adhoc_query_valid_only_groupby() -> None:
+    p: QueryParameters = {"group_by": ["gb"], "limit": 1, "where": ["1=1"], "order_by": ["gb"], "read_cache": False}
+    r = validate_query_parameters(p)
+    assert isinstance(r, AdhocQueryParametersStrict)
+    assert r.metrics is None
+    assert r.group_by == ["gb"]
+    assert r.order_by == [OrderByGroupBy(name="gb", grain=None)]
+    assert r.where == ["1=1"]
+    assert r.limit == 1
+    assert not r.read_cache
+
+
 def test_validate_query_params_saved_query_valid() -> None:
     p: QueryParameters = {
         "saved_query": "a",
@@ -214,15 +226,6 @@ def test_validate_query_params_saved_query_valid() -> None:
     assert not r.read_cache
 
 
-def test_validate_query_params_adhoc_query_no_metrics() -> None:
-    p: QueryParameters = {
-        "metrics": [],
-        "group_by": ["a", "b"],
-    }
-    with pytest.raises(ValueError):
-        validate_query_parameters(p)
-
-
 def test_validate_query_params_saved_query_group_by() -> None:
     p: QueryParameters = {
         "saved_query": "sq",
@@ -239,6 +242,6 @@ def test_validate_query_params_adhoc_and_saved_query() -> None:
 
 
 def test_validate_query_params_no_query() -> None:
-    p: QueryParameters = {"group_by": ["gb"], "limit": 1, "where": ["1=1"], "order_by": ["a"], "read_cache": False}
+    p: QueryParameters = {"limit": 1, "where": ["1=1"], "order_by": ["a"], "read_cache": False}
     with pytest.raises(ValueError):
         validate_query_parameters(p)